Highly filled, dense, thermoplastic based compositions which have ceramic-like properties are desirable because they may be used in applications usually reserved for ceramics or filled thermosets. This is because of the relative ease with which thermoplastics may be fabricated. In the above-mentioned copending application, the applicants in this commonly assigned application have reported that certain polymers may be combined with exceptionally high levels of inorganic fillers to result in molding compositions which are capable of being molded into articles having ceramic-like properties. These polymers are selected from the group consisting of polycarbonates, polyetherimides and copolymers thereof, polycyclohexyldimethylene terephthalates and copolymers thereof, polypropylene and polybutylene terephthalates and copolymers thereof, polyethylene terephthalates and copolymers thereof, polyimides, polyester carbonates, polyphenylene sulfides, polyamides, polyamideimides, polyarylates, polymethylpentenes, polysulfones, polyether sulfones, polystyrenes, rubber modified high impact polystyrenes, acetals, SAN, SMA, ASA, modified polyphenylene ethers, polyether ketones, ABS, PVC, PFA, ECTFE, ETFE, PVDF, liquid crystal polymers and combinations thereof. Such thermoplastics, and mixtures of any of them are combined with 30%-80% by weight of a filler selected from zinc oxide or barium sulfate, zirconium oxide, zirconium silicate or mixtures of any of them.
It has now been discovered that many new polymer blends comprising polyesters derived from cyclohexanedimethanol and a hexacarbocyclic dicarboxylic acid having high loadings of the mineral fillers over a broad resin composition range will surprisingly provide highly dense, highly heat-resistant, readily processible compositions. They will also have high impact strength, especially if an effective amount of an impact modifier comprising a thermoplastic elastomer is included in the composition, which also enhances flow properties in a desirable manner. Addition of the thermoplastic elastomers, for example copolyether esters, copolyetherimide esters, styrene/acrylonitrile-modified EPDM terpolymers, ethylene glycidyl methacrylate copolymers, and the like, to the highly filled highly dense linear polyester compositions is also found to provide desirably lower modulus, paintability, extrudability and injection moldability. The new compositions can also contain reinforcing fillers and/or flame retardant agents.
The new compositions may be used to mold useful objects such as tableware, dishes, bowls, mugs, plumbing fixtures and the like which require a smooth surface. In addition, the selection of the proper level of filler will provide a density in the molded article which approaches the density of ceramics, e.g., 2.0 to 2.5 g/cc.
Accordingly, it is an object of this invention to provide novel molding compositions which contain a high level of fillers which will provide a smooth surface.
It is also an object of this invention to provide novel molding compositions which have a high level of fillers which will have a ceramic-like feel and density.
It is also an object of this invention to provide novel molding compositions having special utility for making molded articles.
It is also an object of this invention to provide novel molding compositions which may be employed for making highly dense molded articles.
These and other objects of the invention will become apparent from the present specification.